Questions in mathematics

Questions in mathematics

[Free] What is the sum? [tex]$\frac{3}{x^2-9}+\frac{5}{x+3}$[/tex]

[Free] Select the correct answer. Insect larvae grow incredibly quickly over the first several days of their lives. The length of one particular species increases exponentially at a rate of $25\%$ each day. A scientist studying this species of larva measures one specimen to be $3 ~ mm$ in length at the beginning of his observation period. The scientist will transfer the larvae to a new environment once the larvae are over 9.15 millimeters long. If $t$ represents the number of days since the scientist began his observations, write an inequality to represent the situation, and use it to determine after how many days the larvae are transferred to the new environment. A. $t<6$ B. $t>9$ C. $t<3$ D. $t>5

[Free] The slope for the line with points $(-1,5)$ and $(2,2)$ is $\frac{3}{3}$. True or False?

[Free] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Free] Evaluate [tex]$\lim _{x \rightarrow 0} \frac{x}{\sin ^{-1}(3 x)}=$[/tex]

[Free] Use a graphing calculator to sketch the graph of the quadratic equation, and then state the domain and range. [tex]y=2 x^2-x+3[/tex] A. D : all real numbers, R :[tex](y \geq 2.875)[/tex] B. D : all real numbers, R: [tex](y \leq 3)[/tex] C. D: [tex](y \leq-0.25)[/tex], R: [tex](y \leq 2.875)[/tex] D. D : all real numbers, R :[tex](y \leq 3.125)[/tex]

[Free] The sum of two numbers is 45 and the mean proportional between them is 18. The numbers are: a) (15, 30) b) (32, 13) c) (36, 9) d) (25, 20)

[Free] Which of the following statements are true about scalar multiplication of matrices? You can multiply a matrix of any size by a scalar. For any matrix $A, 1 \times A=A$. For any scalar $r, r l=l$, where $l$ is the identity matrix. You can scale geometric figures using scalar multiplication. Scalar multiplication is a shortcut for repeated addition of the same matrix. Scalar multiplication is not possible for matrices that are not square.

[Free] Simplify this expression: $4(1-3 x)+7 x-8$

[Free] \frac{2}{2-y}+\frac{3}{y+2}=\frac{2 y}{y^2-4}